Sand trap for use in well bores



May 2, 1957 J. R. BROWN 3,316,971

SAND TRAP FOR USE IN WELL BORES A TTONSV May 2, 1967 J. R. BROWN SANDTRAP FOR USE IN WELL BORES 2 Sheets-Sheet 2 Filed Feb. l2. 1965 JFRBROWNINVENTOR.

/4 TTO/P/VEY United States Patent Olitice 3,316,971 Patented May 2, 1967This invention relates to improvements in sand traps, junk catchers orthe like, for use in well bores.

In the operation of wells, such as oil and gas wells, which employ pipestrings carrying various types of tools positioned inside a well casing,the accumulation of sand and other detritus settling down on top of thewell tools in the well bore frequently creates a severe problem inconnection with the removal of well strings and the tools carriedthereon.

To meet this problem, various types of sand traps, junk catchers or thelike have been designed for installation in the pipe string above thetools, which are more commonly well packers, anchors, down-well pumps,and the like. These prior art traps have generally been rathercomplicated in construction, frequently requiring varied manipulationsof the pipe strings in order to release them for removal and have beengenerally inefticient in their primary purpose of trapping sandsettlings and other detritus while permitting the pipe string andattached tools to be removed from the well when necessary.

Accordingly, it is a primary object of this invention to provide agreatly simplified, economical design of trap which obviate-s thedisadvantages of prior designs and which is highly effective both forpreventing accumulation of settlings and detritus on the well tools andfor ready release when it is necessary to remove the pipe string and thetool supported thereon.

An important object is the provision of a trap construction which isoperated entirely by longitudinal movements of the supporting pipestring.

A ymore specific object is the provision of a trap structure employingan upwardly facing, iiexible cup-type catcher element slidably disposedfor relative longitudinal movement on a mandrel having by-pass passagesand effective, in response to said longitudinal movement, to open andclose said by-pass passages, the catcher element being operative in theclosed position of the passages to seal the annular space between thepipe string and the well bore wall.

Other and more speciiic objects of this invention will become morereadily apparent from the following detailed description when read inconjunction with the accompanying drawing which illustrates a usefulembodiment in accordance with this invention.

In the drawing:

FIG. 1 is a longitudinal, quarter sectional view of the trap apparatusillustrating the positions occupied by the parts as the device is beingrun into a well;

FIG. 2 is a view similar to FIG. 1 showing the positions of the partswhen the device is being withdrawn from the well; and

FIG. 3 is a view similar to FGS. 1 and 2 showing the parts in theposition occupied when the catcher element is in sealing position in thewell.

Referring to the drawing, the device comprises a tubular mandrel 10, apositioning sleeve 11 slidably mounted about the mandrel, and anupwardly facing cup-type trap o1' catcher element 12 slidably mounted onthe upper portion of mandrel above positioning sleeve 11.

Mandrel 16 is adapted to be installed between upper and lower sections Pand P', respectively, of a tubing string which extends into the bore ofa well casing C. The upper end of mandrel 101 has a threaded socket 14for receiving the lower end of upper pipe section P and has anexternally threaded lower end portion 15 receivable in the upper portion16 of a tubular sub or adapter 17, the lower end of which is threadedfor connection to lower pipe section P by a conventional collar 18, orthe like.

The exterior of mandrel ll()` is reduced in diameter in a series ofsteps beginning at a point near the upper end thereof where the firstreduction delincs the annular, downwardly facing shoulder 19'; thesecond reduction in diameter is at an intermediate point along themandrel and defines the downwardly facing annular shoulder 20 (best seenin FIG. 2) and the third reduction in diameter occurs near the lower endof the mandrel defining the exteriorly threaded lower pin portion 15.

Catcher element 12 is slidably disposed on the portion of mandrel 10below shoulder 19y and above upper end face 21 of positioning sleeve 11.Shoulders 19 and 21 thus provide the limits for relative longitudinaltravel between the mandrel and catcher element 12.

`Catcher element 12 is of a generally conventional cupshapedconfiguration having its 4mouth portion 22 opening upwardly and dened bythe flexible lip 23 which is dimensioned to normally be in sldableengagement with the ybore wall of casing C. The lower end portion ofcatcher element 12 comprises the base section 24 having an axial bore25l dimensioned to slidably fit closely about the exterior of mandrel10' extending between shoulders 19 and 20. The upper face of basesection 24 defines an upwardly facing annular shoulder 26 adapted toabut shoulder 19 for limiting upward movement of ctacher element 12relative to the mandrel.

Mandrel Ill has a series of angularly spaced longitudinal grooves 27 inthe outer periphery thereof which open to the exterior of the mandrelabove shoulder 19 and to a point which will rbe below the lower end ofcatcher element 12 when the latter is in its uppermost position, shownin FIG. 1. A second series of angularly spaced, longitudinal grooves 28are provided in the exterior of mandrel ltlfextending from a pointspaced below the lower ends of grooves 27 to a point a short distancebelow shoulder Ztl'. The portion of mandrel 10 extending between thelower ends of grooves 27 and the upper ends of grooves 28` constitutes acylindrical sealing area 29 adapted to provide a non-slotted surfacewhich is disposed for sealing engagement by base portion 24 of thecatcher element, as will appear subsequently.

The lower end of positioning sleeve 11 is slidably disposed over theupper reduced diameter portion 30 of adapter 17 which defines theupwardly facing shoulder 31 adapted to form a stop for the lower end ofsleeve 11 in its longitudinal movements relative to the mandrel. Reducedportion 30 is provided with a series of angularly spaced, longitudinallyextending grooves 32 adapted to receive guide pins 33` projectinginwardly from the lower end of sleeve 11. The upper and lower ends ofgrooves 32 are deiined by walls forming shoulders 34 and 35,respectively, and are adapted to be engaged by guide pins 33 to limitthe relative longitudinal travel of sleeve 11. The upper end of sleeve11 is provided with a plurality of angularly spaced, verticallyextending slots 36 vhich open through the upper end of the sleeve andtre angularly positioned to be substantially in regis- ;er with grooves28 in the mandrel. Sleeve 11 is provided at a point just below the lowerends of slots 36 with an inwardly extending annular enlargement definingan upwardly facing shoulder 3'7 and a downwardly facing shoulder 38.Upwardly facing shoulder 37 is adapted to be engaged by shoulder 2li onthe exterior of the mandrel for limiting upward movement of sleeve 11relative to the mandrel. The radial dimensions of mandrel and sleeve 11are made such as to define an annular space 39 between the sleeve andthe mandrel between shoulder 38 and the upper end of adapter portion 16.A coil spring 40 is disposed in compression in annular space 39, havingits opposite ends bearing, respectively, against shoulder 38 and theupper end of adapter portion 16, whereby to normally bias sleeve 11upwardly relative to mandrel 10. Sleeve 11 is provided with a pluralityof vent or relief ports 41 through the wall thereof below shoulder 38 toprevent trapping of uid in the annular space during relative movement ofthe sleeve.

In operation, the device will be installed between pipe sections P andP', as shown in FIG. l, and will be run into a well bore. It will beunderstood that other tools, such as packers, anchors, down-well pumps,and and the like will be mounted below the trap device on pipe sectionP. When the pipe string is run into the well carrying the trapstructure, the friction between lip 23 of the catcher element and thewell wall, as represented by' casing C, will restrain the catcherelement suiciently to allow shoulder 19 on the mandrel to engageshoulder 26 of the catcher element, pushing the latter downwardly withthe pipe string. The force of spring 40 will hold sleeve 11 in itsupward position, also as shown in FIG. l. With the parts in the positionshown in FIG. 1, it will be seen that grooves 27 will extend from belowcatcher element 12 to points above base 24 of the latter so as toprovide a plurality of by-pass passageways through the catcher elementfor fluid encountered in lowering the tools into the well bore.

When the tool string has attained its desired position in the well,catcher element 12 will settle down along the mandrel under its ownweight and the weight of any liuid thereabove until the lower end ofbase section 24 comes into contact with end face 21 of the sealingsleeve. At this point, it will be seen that base 24 will be opposite andsurrounding the non-slotted section 29 of the mandrel and will form aseal therewith, as best seen in FIG. 3. Thus, any sand or other detritussettling down from above will be trapped in catcher element 12, sincethe latter will have sealed off between portion 29` and the wall ofcasing C. Thus, no such settlings or detritus can pass below the catcherelement and will thereby be kept o'f of the equipment or tools in thewell -below the catcher element.

When it is desired to pull the pipe string and its supported equipmentfrom the well, an upward force applied to the pipe string will pullmandrel 10 upwardly relative to catcher element 12 which will be-frictionally held against the wall of casing C by the load of settlingstrapped therein. This relative upward movement of the mandrel will movethe latter upwardly until upper end face 21 of positioning sleeve 11abuts the lower end of the catcher element, as seen in FIG. 2. Continuedupward movement of the pipe string will move the mandrel upwardlyrelative to sleeve 11 compressing spring 40 because of the resistanceoliered by catcher 12 seated on the upper end of the sleeve, until guidepins 33 engage bottom shoulders 35- of grooves 32. This terminatesupward movement of the mandrel relative to catcher element 12 andpositioning sleeve 11. At this point, it will be seen that grooves 28now form by-pass passages around base portion 24 of the catcher elementso that as the tool String is drawn upwardly through casing C fluidabove catcher element 12 will by-pass the latter through grooves 28 tothe annular space below the catcher element, the lower ends of grooves28 being in communication with slots 36 in the upper end of sleeve 11.While some very iine sand may pass downwardly through the by-passpassages when grooves 28 are thus opened, this will generally not besuicient to interfere with the removal of the tool string as the slotswill ordinarily be dimensioned to prevent the passage of largerfragments which might otherwise prevent release of the tool string.

From the foregoing, it will be seen that this device provides acomparatively simple, easily operated, and efficient sand trap or junkcatcher having the various advantages noted previously.

it will be understood that various changes and modifications may be madein the details of the illustrative embodiment within the scope of theappended claims but without departing from the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

1. A device for trapping detritus settling in a well bore, comprising, atubul-ar mandrel connectible into a well pipe string to form a partthereof, longitudinally spaced-apart upper and lower elongate groovemeans in the exterior of said mandrel, a non-grooved cylindrical sealingsection separating said upper and lower groove means, an upwardly facingcup-shaped catcher element slidably disposed on the mandrel for relativelongitudinal movement thereon between an upper by-pass position oppositesaid upper groove means, an intermediate position -about said sealingsec-tion, and a lower by-pass position opposite said lower groove means,a positioning sleeve means longitudinally slidably `disposed about saidmandrel below said catcher element for movement between an upperposition adapted to stop said catcher element at said intermediateposition and a lower position permitting the catcher element to attainsaid lower by-pass position, means resiliently biasing said sleeve meanstoward said upper position, and means limiting relative upward movementof said catcher element to said upper by-pass position.

2. A device according to claim 1 wherein said catcher element includes aiiexible lip portion about its upper end slidably engageable with asurrounding well wall, and a base portion having an axial bore adaptedfor close iitting engagement aboutsaid sealing section.

3. A device according to claim 1 wherein s-aid lastmentioned meanscomprises cooperating shoulders on said mandrel and said catcher elementabuttable upon attainment by the catcher element of said upper by-passposition.

4. A device for trapping detritus settling in a well bore, comprising, atubular mandrel connectible into a well pipe Istring to form a partthereof, longitudinally spacedapar-t upper and lower elongate groovemeans in the exterior of said mandrel, a non-grooved cylindrical sealingsection separating s-aid upper and lower groove means, an upwardlyfacing cup-shaped catcher element slidably disposed on the mandrel forrelative longitudinal movement thereon between an upper by-pass positionopposite said upper groove means, an intermediate position about saidsealing section, and a lower by-pass position opposite sai-d lowergroove means, a positioning sleeve means longitudinally slidablydisposed about said mandrel below said catcher element for movementbetween an upper position adapted to stop said catcher element at saidintermediate position and a lower position permitting the catcherelement to `attain said lower by-pass position, means resilientlybiasing said sleeve means toward said upper position, means limitingrelative upward movement of said catcher element to said upper by-passposition, and means limiting the movement of said sleeve means to saidupper and lower positions.

5. A device according to claim 4 wherein said catcher element includesan outwardly aring exible lip portion ing section, said base portionhaving a length less than.

that of said upper grooves, and wherein said means limiting relativeupward movement of said catcher element comprises cooperating shoulderson said mandrel and s-aid catcher element abuttable upon attainment bythe catcher ele-ment of said upper by-pass position.

6'. A device according to claim 4 wherein the upper end portion of saidsleeve means is provided with openings registering With said lowergroove means at both said upper and lower positions.

References Cited by the Examiner 5 UNITED STATES PATENTS 2,786,5343/1957 Page 166-183 X 2,935,132 5/1960 Arterbury et al. 166--202 X3,066,614 12/ 1962 Grandstaf 103--225 10 CHARLES E. OCOINNELL, PrimaryExaminer.

D. H. BROWN, Assistant Examiner.

1. A DEVICE FOR TRAPPING DETRITUS SETTLING IN A WELL BORE, COMPRISING, A TUBULAR MANDREL CONNECTIBLE INTO A WELL PIPE STRING TO FORM A PART THEREOF, LONGITUDINALLY SPACED-APART UPPER AND LOWER ELONGATE GROOVE MEANS IN THE EXTERIOR OF SAID MANDREL, A NON-GROOVED CYLINDRICAL SEALING SECTION SEPARATING SAID UPPER AND LOWER GROOVE MEANS, AND UPWARDLY FACING CUP-SHAPED CATCHER ELEMENT SLIDABLY DISPOSED ON THE MANDREL FOR RELATIVE LONGITUDINAL MOVEMENT THEREON BETWEEN AN UPPER BY-PASS POSITION OPPOSITE SAID UPPER GROOVE MEANS, AN INTERMEDIATE POSITION ABOUT SAID SEALING SECTION, AND A LOWER BY-PASS POSITION OPPOSITE SAID LOWER GROOVE MEANS, A POSITIONING SLEEVE MEANS LONGITUDINALLY SLIDABLY DISPOSED ABOUT SAID MANDREL BELOW SAID CATCHER ELEMENT FOR MOVEMENT BETWEEN AN UPPER POSITION ADAPTED TO STOP SAID CATCHER ELEMENT AT SAID INTERMEDIATE POSITION AND A LOWER POSITION PERMITTING THE CATCHER ELEMENT TO ATTAIN SAID LOWER BY-PASS POSITION, MEANS RESILIENTLY BIASING SAID SLEEVE MEANS TOWARD SAID UPPER POSITION, AND MEANS LIMITING RELATIVE UPWARD MOVEMENT OF SAID CATCHER ELEMENT TO SAID UPPER BY-PASS POSITION. 